1. Field of the Invention
This invention relates to a controlling device for controlling a Chinese character printer which prints characters, particularly Chinese characters, on print paper, and more particularly to a controlling device which controls a Chinese character printer such that while the printer is not performing printing, a character pattern may be written into a font memory in order to allow an input process to be performed without a delay from an output process to allow the printer to perform printing without the necessity of waiting.
2. Description of the Prior Art
Generally, a printer which prints information processed by a processing unit or the like as characters, numerals and marks on print paper is used as one of peripheral equipments of various computers. Such a printer can print various characters, but particularly a printer which has a function to print Chinese characters, there is a problem a little different from a printer for the exclusive use for alphabetic characters, numerals and marks due to the large of the number of Chinese characters. FIG. 1 is a block diagram showing a controlling device which is applied to a conventional Chinese character printer. Referring to FIG. 1, reference numeral 1 denotes a host computer, 2 a temporary storage buffer for temporarily storing therein print data and character patterns received from the host computer 1, 3 an unregistered character code table for storing therein unregistered character codes within the temporary storage buffer 2, 4 a character pattern registration check table for storing therein information regarding whether or not a character pattern is registered, 5 a page buffer for storing print data therein, 6 a font memory for storing character patterns therein, 7 a printer, and 8 a pattern converting unit for receiving a character pattern via an output controlling unit 10 and for delivering the received character pattern to the printer 7.
Reference numeral 9 denotes an input controlling unit. The input controlling unit 9 reads contents of the temporary storage buffer 2, and, if the contents are print data, then it studies a character code of the print data with the character pattern registration check table 4 and if the character code is not yet registered, the input controlling unit 9 sets the character code into the unregistered character code table 3 and writes the print data into the page buffer 5. To the contrary, if the contents of the temporary storage buffer 2 are a character pattern, then the input controlling unit 9 rewrites contents of a cell of the character pattern registration check table 4 corresponding to the character as registered and then writes the character pattern into the font memory 6.
Reference numeral 10 denotes an output controlling unit which reads out print data from the page buffer 5 and transfers the print data thus read out to the pattern converting unit 8.
FIG. 2 is a detailed view of the unregistered character code table 3. Referring to FIG. 2, reference symbols 3a to 3n individually denot n unregistered character codes, and reference symbol 3x denotes an empty cell of the unregistered character code table 3.
FIG. 3 is a detailed view of the character pattern registration check table 4, and in FIG. 3, reference symbols 4a to 4n indicate corresponding relationships to character codes, and the contents "0" represent "unregistered" and "1" represent "registered".
FIG. 4 is a detailed view of the page buffer 5. Referring to FIG. 4, reference symbol 51 denotes a write address register, 52 a read-out address register, "5w" a write address, "5r" a read-out address, 53 an empty area, 54 an area in which print data are present, 54a a character code.
FIG. 5 illustrates information stored in the temporary storage buffer 2, and in FIG. 5, reference symbol 2a denotes an area in which print data are stored, 2b an area in which a character pattern is stored, reference symbols 2a.sub.1 to 2a.sub.n denote each a character code within the print data area 2a, reference symbol 2b.sub.1 denotes a character code within the character pattern area, and 2b.sub.2 a pattern of a character within the character pattern.
FIG. 6 illustrates results of printing, and in FIG. 6, references symbol 7a denotes a zone in which patterns are printed, and 7b a zone in which no pattern is printed and only paper feeding is effected.
Now, operation of the controlling unit will be described. At first, input operation will be described.
If a notice is received from the host computer 1, the input controlling unit 9 delivers print data and character patterns received from the host computer 1 to the temporary storage buffer 2 and then effects following operations individually for the print data and the character patterns.
In case of the print data, character codes 2a.sub.1 to 2a.sub.n within the temporary storage buffer 2 are read out one after another therefrom and are then checked whether or not they are already registered with the character pattern registration check table 4. In particular, if contents i of a cell of the character pattern registration check table 4 corresponding to a character code 4n are "0", then it is determined that the character pattern is not yet registered, and on the contrary if contents i are "1", then it is determined that the character pattern is already registered. Here, such a character which is not yet registered is registered into the unregistered character code table 3.
Then, the input controlling unit 9 writes the contents of the temporary storage buffer 2 into cells of of the page buffer 5 beginning with that one of cells which is designated by the write address register 51 and then updates contents of the write address register 51.
After completion of the processes described above, the input controlling unit 9 delivers contents of the unregistered character code table 3 to the host computer 1.
Normally, the host computer 1 delivers character patterns for the characters corresponding to the contents within the unregistered character code table 3 to the Chinese character printer controlling device.
Thus, in case a character pattern is received from the host computer 1, the input controlling unit 9 at first fetches the character code 2b.sub.1 of the character pattern from the temporary storage buffer 2 and rewrites contents of a cell of the character pattern registration check table 4 corresponding to the character to "1".
Then, the input controlling unit 9 transfers the pattern 2b.sub.2 from the temporary storage buffer 2 to the font memory 6.
Through the operations described above, the print data within the print data area 2a are written into the page buffer 5 and the character pattern within the character pattern area 2b is written into the font memory 6.
Now, outputting operation will be described mainly with respect to operation of the output controlling unit 10. The output controlling unit 10 fetches a character code 54a from a cell of the page buffer 5 designated by the address register 52 and then fetches a corresponding pattern from the font memory 6 and delivers it to the pattern converting unit 8.
The pattern converting unit 8 re-arranges the pattern received from the output controlling unit 10 and delivers it to the printer 7. Details of the operation of the pattern converting unit 8 are omitted herein because they have no direct relation to the scope and spirit of the present invention.
The output controlling unit 10 repeats such a series of operations with the read-out address register 52 for the page buffer 5 updated for each repetition.
In this manner, printing is effected in accordance with the print data stored in the page buffer 5.
However, since the conventional controlling device for a Chinese character printer has such a construction as described above, during outputting operation of the controlling device wherein outputting is being conducted from the pattern converting unit to the printer, writing into the font memory as an input process operation cannot be performed and hence input process becomes delayed relative to output process. As a result, there is a problem that output printing is delayed and hence the printing speed becomes low, resulting in deterioration in printing capacity of the printer.